FIG. 1 depicts top and side views of a portion of a conventional energy assisted magnetic recording (EAMR) transducer 10. For clarity, FIG. 1 is not to scale. The conventional EAMR transducer 10 is used in writing a recording media (not shown in FIG. 1) and receives light, or energy, from a conventional laser (not shown in FIG. 1). The conventional EAMR transducer 10 includes a conventional waveguide 12 having cladding 14 and 16 and core 18, a conventional grating 20, a conventional near-field transducer (NFT) 22, and a conventional pole 30. The conventional NFT 22 is typically composed of Au or Ag.
In operation, light from a laser (not shown) is incident on the grating 20, which coupled light to the waveguide 12. Light is guided by the conventional waveguide 12 to the NFT 22 near the air-bearing surface (ABS). The NFT 22 utilizes local resonances in surface plasmons to focus the light to magnetic recording media (not shown), such as a disk. The surface plasmons used by the NFT 22 are electromagnetic waves that propagate along metal/dielectric interfaces. At resonance, the NFT 22 couples the optical energy of the surface plasmons efficiently into the recording medium layer with a confined optical spot which is much smaller than the optical diffraction limit. This optical spot can typically heat the recording medium layer above the Curie point in nano-seconds. High density bits can be written on a high coercivity medium with a pole 30 having modest magnetic field.
Although the conventional EAMR transducer 10 may function, there are drawbacks. The conventional NFT 22 is typically optimized for higher coupling efficiency. For example, the conventional NFT 22 may consist of metals such as Au and Ag to improve the optical efficiency of the conventional NFT 22 above that of other metals. Although a higher optical efficiency is desired to coupling energy to the media (not shown), this also means that the conventional NFT 22 is heated during use. Under extreme conditions, the melting point of the conventional NFT 22 may be approached or reached. Even at lower working temperatures, the conventional NFT 22 may deform. This deformation generally causes the conventional NFT 22 to protrude from the ABS. The conventional NFT 22 may contact the disk or otherwise become damaged. Further, the NFT 22 may undergo plastic as well as elastic deformation, which permanently changes the geometry of the conventional NFT 22. Thus, performance and reliability of the conventional EAMR head 10 may be adversely affected.
Accordingly, what is needed is a system and method for improving performance and reliability of an EAMR transducer.